My advice is save the document on your computer, not the actual physical piece of paper. It takes up much less space to save a 20 kb sized document than it does to save the 10 pieces of paper you printed it out on.
However, if you turned in your paper, and recieved it back with comments from your teacher/professor written on it, and wish to keep these, my suggestion would be to scan the document onto your computer, and save it as a PDF. Still takes up less space than physical paper, and you can pretty much save it indefinitely.
Besides, it's always fun to look back to the things you were learning a few years ago to see how much you've learned since then.
Bookmarks